In order to build superior taste into edible oil products, they must undergo certain processing steps. The most important, from a finished flavor standpoint, is deodorization. Since the senses of taste and smell are closely linked, deodorization also improves the flavor of the product. The finished product is ideally a bland oil.
About the middle of the last century, deodorization of fats was practiced in Europe by blowing steam through the heated oils. Prior to the turn of the century, steam blowing was used in connection with evacuation for the improvement of fats used in margarine products. About 1900 David Wesson, in the United States, designed a greatly improved steam-vacuum deodorizer. The system successfully avoided air contamination, which is one of the important prerequisites of this high-temperature treatment. The process was never patented, but its secrecy was so effectively guarded that for a great many years competitive efforts failed to match the quality of the products that were treated in the Wesson system.
In addition to improved batch processes, semi-continuous and continuous deodorizers were later developed. The theoretical aspects of steam stripping are governed by Raoult's law and Dalton's law.
Vernon Young in an article published in Chemistry and Industry Sept. 16, 1978, pp. 692-703, provides an excellent review of processing currently in use for refining and modifying oils and fats.
High temperature deodorization systems require large amounts of energy, but they can be designed for heat recovery to save energy. For example, a deodorizing system modification for heat recovery and steam refining of palm oil is reported by Gavin et al in J. Am. Oil Chemists Soc., November 1973 (Vol. 50), pp. 446A-472A, incorporated herein by reference in its entirety. Also, U.S. Pat. No. 3,607,670, King, Sept. 12, 1971, relates to a deodorization process in which the heat exchange between incoming cold oil and outgoing hot oil takes place within an enclosed vessel.
The problem of bland oil regression (degradation), however, is a drawback to energy efficient deodorization systems, and particularly prior art modified systems where hot, freshly deodorized oil is held dormant, dwells or is pumped out of the deodorizer at too high of a temperature. Such oils degrade from a bland taste to a scorched or rubbery taste, or degrade to various other flavors which are less than bland.
Thus, there was a need to invent a process whereby optimum heat is utilized and the bland taste of deodorized oil is maintained in energy efficient systems.
It is an object of the present invention to prevent degradation of bland flavor in hot, freshly deodorized oil in high temperature deodorization systems where said oil is held dormant for further processing.
It is another object of the present invention to provide a method to maintain optimum good taste and bland flavor in freshly deodorized oil.
Another object of the present invention is to maximize heat recovery in high temperature deodorization systems while maintaining bland deodorized oil flavor.
Other objects will become apparent in the light of the disclosure.